跳转到内容

马蹄涡

维基百科,自由的百科全书
机翼等升力分布下形成的马蹄涡
升力突变导致了突变处形成新涡线
真实升力分布下形成的复杂涡线

马蹄涡(英语:horseshoe vortex)是一种简化的机翼涡系模型,由跟随机翼运动的等环量附着涡(bound vortex)和在左、右翼尖处形成的翼尖涡组成。这三条涡线形成类似马蹄的形状,马蹄涡也因之得名。[1][2]此外,当机翼在流场中从静止开始起动时,另有一起动涡从机翼后脱落,但很快因黏性而耗散。[3]同时,远离飞行器的翼尖涡也同样因此而耗散。

翼尖涡会导致下洗气流的产生,进而引起诱导阻力[4]

马蹄涡模型假设环量沿翼展不变(此时由库塔-儒可夫斯基定理可知升力亦沿翼展不变),但这与实际情形并不相符。在更接近实际的升力线理论中,旋涡强度沿翼展方向不断变化,强度的改变导致涡从整个机翼后缘脱落形成涡面,而非仅在左、右翼尖处形成涡线。[5]

参考文献

  1. ^ Millikan, Clark B., Aerodynamics of the Airplane, Figure 1.35
  2. ^ McCormick, Barnes W., Aerodynamics, Aeronautics, and Flight Mechanics, Chapter 3
  3. ^ Shed Vortex. NASA Glenn Research Center. [April 11, 2015]. (原始内容存档于2015-04-06). 
  4. ^ McCormick, Barnes W., Aerodynamics, Aeronautics, and Flight Mechanics, Chapter 4
  5. ^ McCormick, Barnes W., Aerodynamics, Aeronautics, and Flight Mechanics, Figure 4.21
  • Anderson, John D. (2007), Fundamentals of Aerodynamics, Section 5.3 (4th ed.), McGraw-Hill, New York NY. ISBN 978-0-07-295046-5
  • Clancy, L.J. (1975), Aerodynamics, Section 8.10, Pitman Publishing Limited, London ISBN 0-273-01120-0
  • Cook, N.J. (1985), The designer's guide to wind loading of building structures, Part 1, Butterworths, London ISBN 0-408-00870-9
  • McCormick, Barnes W., (1979), Aerodynamics, Aeronautics, and Flight Mechanics, John Wiley & Sons, Inc. New York ISBN 0-471-03032-5
  • Millikan, Clark B., (1941), Aerodynamics of the Airplane, Section 1-6 John Wiley and Sons, Inc., New York
  • Penwarden, A.D., Wise, A.F.E., (1975) Wind environment around buildings, HMSO, London ISBN 0-11-670533-7.
  • Piercy, N.A.V. (1944), Elementary Aerodynamics, Article 213, The English Universities Press Ltd., London.
  • Von Mises, Richard, (1959), Theory of Flight, Chapter IX - section 4, Dover Publications, Inc., New York ISBN 0-486-60541-8